In one type of a fixer that is used to fix an image on a sheet, electromagnetic induction heating (IH) is employed to heat a fixing belt using a magnetic flux from an exciting coil. The fixer of this type typically includes the fixing belt, a pressing member, a fixing pad, a heat generating element, and an exciting coil. The fixing pad is urged towards an inner surface of the fixing belt to form a nip, and the heat generating element, which is disposed along the inner surface of the fixing belt, generates heat through the electromagnetic induction heating. However, a crack may be produced in a layer of the fixing belt while the fixer is used. As a result, the fixing belt having the crack may have a region that cannot generate sufficient amount of heat to fix the image. Further, another region of the cracked fixing belt may generate excessive amount of heat, and, as a result, the fixing belt may be damaged.